1. Field of the Invention
The present invention relates to a catalyst for diesel particle filter, a preparation method thereof and a soot reduction device for diesel engine including the same. More particularly, the present invention relates to a catalyst for diesel particle filter that can maintain high catalyst activity and implement high nitrogen monoxide (NO) conversion efficiency even though it is used under the high temperature or vulcanization condition for a long time, a preparation method thereof and a soot reduction device for diesel engine including the same.
2. Description of the Related Art
In general, even though a diesel engine has excellent fuel efficiency or output, since combustion is performed in a state where air excessive ratio is high because of a characteristic of a diesel engine, the exhaust amount of carbon monoxide (CO) or hydrocarbon is small in a exhaust gas unlike a gasoline engine, but nitrogen oxides (hereinafter, referred to as “NOx”) and particulate matter (PM) are exhausted in a great amount.
In respect to the exhaustion of the particulate matter (PM), a large reduction is ensured through the combustion control, but since the particulate matter (PM) and NOx are in inverse relationship, if NOx is lowered, the particulate matter (PM) is increased, and the particulate matter (PM) is lowered, NOx is increased, such that it is difficult to control reduction of both of them simultaneously.
Particularly, recently, it is reported that the particulate matter (PM) is the most important main factor that contaminates the atmosphere in various media, and it is known that it harmfully affects a human body. As a method for reducing a particulate matter (PM), a diesel particle filter (DPF) is installed in a diesel vehicle. After the diesel particle filter physically collects the particulate matter (PM) that is exhausted from the diesel engine in the filter, the temperature of the exhaust gas is increased to a predetermined temperature or more by a post injection, such that the particulate matter (PM) that is collected in the filter is combusted, thereby removing it. Recently, in order to cope with the regulation of the exhaust gas that is reinforced over the world, a method for reducing the amount of NOx that is exhausted by providing a device for decomposing or reducing NOx at a front end of the diesel particle filter (DPF).
However, because of the installation of the device for decomposing or reducing NOx, the amount of nitrogen dioxide that inflows to the diesel particle filter (DPF) is largely lowered, such that a natural regeneration effect is largely deteriorated by the reaction of soot and nitrogen dioxide that are collected in the DPF. Therefore, development of a method for satisfying the regulation of the exhaust gas that is applied to diesel engine vehicles and completely removing the exhaust gas and fine dust that are discharged from the diesel engine is required.
The information disclosed in this Background section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.